I don't know the history of Karnataka's flag at all, but I do remember that during the State Day, almost everyone was flying Karnataka's flag (including most of the autorickshaws). It was a two-toned flag, with a red stripe and (I believe) a white stripe. It was not the same colors as the Mysore princely state's flag, which can be found on this website, even though Karnataka is basically the Mysore princely state with a few other "Kannada speaking" areas. In Mysore itself, the royal crest and even pictures of the present Maharaja are everywhere. The Maharaja is still quite respected. He holds no official function, but is consistently elected as Mysore's representative to the state assembly.
Contributed by Bryan Siegfried, 17 March 1999

I visited Karnataka (Bangalore) in mid January and saw many state flags hoisted in buildings. These were red over yellow bicolour flags and people in the state confirmed that it is a current state flag. Nozomi Kariyasu, 21 March 1999

If you have been to Bangalore and had a look around you
will see a peculiar flag (half yellow and half red colour) on the roof
tops of all the big buildings. Almost everyone who comes to Bangalore
will have a question what is this flag, and most of them think it is
the Karnataka Flag. But all of us know that we have one and only flag
which is the Indian tricolour Flag which alone can be used, and none
of the states are allowed to have their own flag.

So how come Karnataka has its own flag, well I did a bit of searching
and found that the flag is not officially or unofficially the
Karanataka Flag. It is actually the flag of a political party "Kannada
Paksha" which was formed in 1965 by one Mr Ma. Ramamurthy, though the
party did not last long, but the flag which is actually the Kannada
Flag stayed on, and is now in the sentiments of the people as the flag
which represents Karnataka. Hence we now find people using this flag
whether for the Karnataka Rajotsava or be it for any protests.

Now are you wondering what is the significance of the yellow and red
colours in the flag, well they stand for Arshina and Kumkuma
respectively. So hope that clears out any misunderstanding that people may have
regarding the flag.

An official proposal for the state flag was presented on March 8th this year.
It is a yellow-white-red horizontal tricolor with the state emblem in center of
white field. The emblem is not depicted in full color, but as a line drawing in
black and white.

The state government, which stands behind the proposal,
claims that adopting the state flag is not against the Constitution of India, as
long as this flag is flown below the national flag. The reaction of central
government is yet to be seen.

What I had thought of as an error - the omission of the motto from the ribbon
in the bottom part - is actually a correct reproduction of what can be seen in
the photos. Why was it done, remains unclear to me - the arms do contain the
motto, so it should have appeared in the flag as well.Tomislav Todorovic,
10 April 2018

From
https://www.thenewsminute.com:The emblem usually carries the words ‘Satymeva
Jayate’ below. "However, the words Satyameva Jayate will not be present on the
flag,"SG Siddaramaiah said.

Presumably they've avoiding the mistake
with the naval ensign, where the flag was simply defined as having the emblem on
it, and thus unintentionally including the motto.Jonathan Dixon, 10
April 2018

This is a representation of the flag of the City Corporation of Bangalore (Bengaluru Mahanagara Palike), capital of Karnataka state in India. The flag has panels of green and yellow, with the Bangalore City Corporation emblem in the centre in a white circle. I have seen this flag flying along with the Indian tricolour over the Corporation headquarters,
but nowhere else in Bangalore. I guess it might be an official flag. The emblem represented in the
image is as I saw it on the Bangalore Corporation website, but the one on the actual flag might differ. Raamesh Gowri Raghavan, 27 May 2002